Self cleaning pulley



Aug. 6, 1957 L. EVERT l 2,801,733

SELF CLEANING PULLEY Filed Nov. 5, 1953 2,801,733 Fatented Aug. 6, 1957 hcc SELF CLEANWG PULLEY Lawrence L. Evert, Euclid, Ohio, assigner to The-Euclid Road Machinery Co., Cleveland,` Ohio, a corporation of Ohio Application November 5, 1953, Serial-No. 390,304

4 Claims. (Cl. 198-230) This invention relates to improvements inia self-cleaning pulley and more particularly to a returnoridler pulley of an earth carrying conveyor belt.

An object of the present invention is to` provide a cleaning means actuatedA by the coaction between a conveyor member and a rolleretype support member over which it passes.

Another objectV- of the present invention is toV provide a cleaning means characterized by its structural simplicity, inexpensive manufacturing cost, and operating efficiency.

Other features of this invention reside in the arrange.- ment and design ofthe parts for carrying out their appropriate functions.

Other objects and advantages of this invention will be' apparent from the accompanying drawings and description and the essential features will be set forth inV the' appendedclaims.

in the drawings,

Fig. l is a fragmental sideu elevational view of a conveyor having` theV present invention onthe lower rollertype support member serving as an idler or return roller;

Fig. 2 is a verticalsectional View taken along the line' 2 2 of Fig. l through the conveyor with the idler roller partially shown in section and1 partially in elevation; while Fig. 3 is a transverse sectionalview along the line 3 3 of Fig. 2 through the conveyor belt member, the rollertype support member, and the cleaning means of the present invention.`

While this invention might be adapted to various types of machines andvarious typesof conveyors, I have chosen toillustrate and. describe. the. samea's applied tok adigging and loading. apparatus more fully described in U. `Patent No. 2,618,083, issued November 1S, 1952, to R. Q. Armington and G. E. Armington, and entitled Excavating and Loading Plow With Endless Conveyor, to which reference may be had for a more complete description of the loader apparatus.

lt is believed suflicient to state 'here that after the earth has been dug -by the loading blade and plow point, it is carried by the upper conveyor run of the loading apparatus to its discharge point. Only `a portion of this apparatus is shown herein. The conveyor portion of the apparatus includes a frame having a pair of opposite side walls 11, 11 between which travel the upper load carrying run 17a of the endless conveyor 17 and the lower or return run 17 b. Both the load carrying run 17a and the return run 17b are supported by rollers.

The present invention relates to the lower roller in Fig. l serving vas the idling or return roller and more clearly illustrated in Figs. 2 and 3. Although only one roller is illustrated, many rollers may make this corresponding contact with the belt type conveyor member. This roller-type member 15 is supported by a pair of brackets 12, 12 forming part of the frame 10 and secured to the lower edges of the side walls 11, 11. Only the bracket 12 on the left in Fig. 2 is shown in detail. This bracket 12 has a cut-out 12a within which is removably held a bearing 14 having parallel slots `cut into opposite sides of its periphery for detachable connection into or out of this cut-out 12a. Stub shafts 15a, 15a', project from opposite sides of the cylindrical roller-type member 15 with shaft 15a supported by the bearing 14.

The other stub shaft 15a' is mounted in a bearing similar to bearing 1li but with va U-shaped key in the parallel peripheral slots thereof so that both the bearing and key may be telescoped endwise into the open left end of sleeve type bracket 12'; rectangular in cross section and non-rotatably holding the bearing and key.

The parts are assembled by sliding the bearing .and key on the right and member 15 endwise toward the right with the hrst two mentioned parts entering sleeve 12. Then, bearing 14 on the left is swung down into cut-out 12a. Hence, the cylindrical roller Vcan serve as a support member 15 over which the return run 17b of the belt type conveyor member 17 passes, andV so that the support member 15 may freely rotate under the drive of the belt 17.

Since theload carrying run 17a of the belt type conveyor member 17 carries the dirt, sticky clay or other material excavated toward the right in Fig.. 1 on its upper surface, this corresponding surface on the returnrun 17h will be on the lower side; and any dirt, sticky clay, etc. will` normally tend to build up lon the idler or return roller 15 unless a suitable cleaning device is provided; The clay and othermaterial will cakexand build up as thick asl/2 or 3%; of an inch under some conditions. This is objectionable since it may interfere with the op'- eration Of the apparatus and may cause changes in belt tension, erratic operation, increase the wear on the belt and apparatus, etc.

The purpose of the present invention is to keep the surface of the cylindrical roller-type support member 15 and the belt type conveyor member 17 free of dirt build-up -by a very simple device. Here, a helical, resilient, coil' spring 118 is fitted loosely over the outer surface of this return or idling `roller-type support member 15. The spring 18 is free to rotate about the roller-type support -member 15 since it is not fastened to the member 15 in any manner but is merely telescoped thereover. The ht between the spring 18 and rollertype member 15 is very loose since the inside diameter ofthe spring is considerably larger than the outside diameter of the roller member 15. The spring 181s freely mountedin Contact with both the roller member 15` andv the belt type conveyor member 17 so that it is driven and affected by the movement of both of these members by frictional contact therebetween. A portion of the spring 18 is located between these members 15 and 17 at all times so that the members will coact together even though the spring 18 is freely mounted thereon and so that spring 18 will serve as an eilicient cleaning means of simple construction and inexpensive cost.

The roller type support member 15 carries end-stop means coacting with the ends of the spring 18 to maintain the telescopic and registering alignment between the parts and the freedom of movement of the spring. This takes the form of collars 19, 19 in Eig. 2 secured to the periphery of the roller type support member 15 at opposite ends to restrain the ends `of the `spring 18.. The ends of the spring 18 are free from and not fixed to these collars 19 with the distance between the collars being substantially the free length of the spring so that the spring 18 is free to rotate about the roller member 15 and to move in any other manner desired in response to the forces exerted upon it by the other structural parts. If the lspring has a long length and large outside diameter, making the distance between the collars the free length of the spring will make it a little too flexible. Then, the spring is slightly increased in length so as to be slightly compressed when between collars 19. However, in either 3 case, the distance between collars 19 is approximately the free length.

The cleaning action is `dependent on the multiplicity of different coactions between the parts in the structure illustrated. First, local vibrations occur between the coils of the spring 18. The tension in the return run 1717 of the belt will cause this run to exert a force against the spring 18 backed up by the roller type support member 15. This force and other forces will cause the spring coils to individually separate or compress or to be twisted in torsion around the central longitudinal axis so that the Spacing between the coils is continually changing and thereby scraping the dirt, sticky clay and other materials oif of the surface of the roller-type support member and the belt-type conveyor member 17 before it has a chance to build up and form a thick cake. Second, the spring coils oscillate radially as they are rotatably driven by the beltetype conveyor member 17 so as to provide a cleaning action. The loose tit of the spring 18 on the roller-type support member 15 makes this possible; the inside diameter of the spring 18 is larger than the outside diameter of the roller-type support member 15. Hence, although the belt-type conveyor member 17 keeps the portion of the spring between it and the roller-type support member 15 held down firmly into contact with the top periphery of this support member, this same belt tension coupled with this looseness of this spring on the roller type support member 15 causes the lower side of the spring 18 in Figs. 2 and 3 most remote from the conveyor member 17 to pull away from the surface of the roller-type member 15 sufficiently far to produce this radial oscillation and to provide the adequate cleaning. This radial movement keeps clean the surface of the roller 15 so that proper belt cleaning can take place at the top of `said roller. Third, the relative rotation between spring 18 and support member 15 caused by the loose connection `therebetween cleans roller 1S. Fourth, any other movements of the spring that provide a cleaning function but have not been mentioned heretofore.

Hence, it should now be clearly understood that the oscillation along the surface of the support member 15 is caused by the driving, frictional contact between the return run 17b of the belt-type conveyor member and the spring 18. The oscillation `of the spring 18 takes two forms. First, a continuous change of spacing between the spring coils with the forces involved tending to change the normal spacing while the resiliency of the spring tending to return the coils to their normal spacing and thus provide an oscillatory movement. Second, a rotational drive of the spring by the belt-type conveyor member 17 causes the spring coils to -oscillate radially as they travel around the axis of rotation of the roller-type support member 15.

Although the preferred form and usage of this invention have been illustrated others will readily occur after a reading of this disclosure. This cleaning device may be used not only on an idler -or return roller but also on a snub pulley, or any other type conveyor roller or pulley or slack eliminating device. The conveyor member may take other forms than an endless belt. Support member 15 may be a stationary support member of cylindrical or any other convenient form instead of a roller adapted to rotate.

Various changes and details and arrangement of parts can be made by one skilled in the art without departing from either the spirit of this invention or the scope of the appended claims.

What I claim is:

1. In combination, a conveyor member, a support member over which said conveyor member passes, and cleaning means engageable with one of said members, said cleaning means being in the form of a helical spring telescoped freely over said support member for oscillation, and the latter being a cylindrical roller support member.

2. In a structure, as set forth in claim l, wherein the telescopic it is of Isufficient 'looseness so that the lower side vof said spring moves radially away from the surface of said roller support member suiiiciently to provide adequate cleaning.

3. In combination, a conveyor member, a support member lover which said conveyor member passes, and cleaning means engageable with one of -said members, said cleaning means being in the form of a helical spring telescoped over said support member and with said latter member carrying end stop means coacting with said spring to maintain the telescopic alignment said spring being free to rotate about Isaid support member.

4. In a structure, as set forth in claim 3, wherein the distance between said end stop means retaining said spring in telescopic alignment is approximately the free length of said spring whereby said spring is free to rotate about said support member.

References Cited in the file of this patent UNITED STATES PATENTS 

